To calculate the exchange current density j0 for the reaction, we need to know the overpotential and the current density j at a specific point on the Tafel plot. Unfortunately, this information is not provided in the problem statement. However, I can provide you with the general formula to calculate the exchange current density if you have the required information:j0 = j / 10^/ba + 10^-/bc where:j0 = exchange current densityj = current density at a specific point on the Tafel plot = overpotential at the same point as the current densityba = anodic Tafel slope 100 mV/decade bc = cathodic Tafel slope 120 mV/decade Please note that the units of the Tafel slopes should be converted to volts/decade e.g., 100 mV/decade = 0.1 V/decade before using them in the formula.